Precisely Actuating Member and Image Tilting Device and Projection System Having Them

ABSTRACT

The present invention relates to a precisely actuating member and an image tilting device and a projection system having them, more particularly, to a projection system comprising a precisely actuating member formed in a one-piece unit to permit a precise rotation movement, an image tilting device for increasing the resolution by precisely adjusting the angle of an image, and a projection system having them. The image tilting device according to the preferred aspect of the present invention comprises a casing. The precisely actuating member is housed in the casing to be integrated therewith for precise reciprocation. A driving member contacts to the precisely actuating member for the movement of the actuating member. A light path conversion member is located on the precisely actuating member to convert the light path by a precise movement.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a precisely actuating member and animage tilting device and a projection system having them, moreparticularly, to a projection system comprising a precisely actuatingmember which can rotate precisely by being integrated, an image tiltingdevice for increasing the resolution by precisely adjusting the angle ofan image, and a projection system having them.

2. Description of the Related Art

Projection systems are used to display small images on large screen bymeans of optical means, which are classified as a CRT (Cathode Ray Tubeprojection), a LCD (Liquid Crystal Display) projection, and a DLP(Digital Light Processing projection) according to the kind of imagesdisplay element.

A CRT projection system, which is the oldest method, displays images ona screen by reflecting images of a small high-resolution cathode raytube onto a mirror.

In an LCD projection system, a small LCD of the size of about 4 incheswithin a projection TV receives the outside regeneration image signalssent to the projection TV to reproduce the images. Thereafter, theimages displayed on a screen is exposed by a strong beam behind theliquid crystal display so that the display is magnified and reflected ona mirror to be projected on the screen.

A DLP projection system operates in such a way as to magnify and projectimage signals inputted from the outside by use of DMD (DigitalMicromirror Device) semiconductor chip in which hundreds of thousands ofminutely actuating mirrors invented by Texas Instrument, Inc. areintegrated.

Such DLP projection system is disclosed in U.S. Pat. No. 6,582,080 ofImax Corporation.

FIG. 1 shows schematically the principal element of a projection systemin accordance with the prior art. Reference numeral 20 represents alight source which projects a beam of light 22 on a projection screen 24via a projection lens 26. The light beam 22 is optically split into red,green and blue components (R, G, B) by a beamsplitter comprising anassembly of prisms 30. The respective components are directed to threecorresponding DMDs 32 by the beamsplitter.

The DMDs are essentially identical but deal with different portions ofthe spectrum. In other words, the light that enters the beamsplitter issplit into red, green and blue components, which are delivered to therespective R, G and B DMDs. The beamsplitter then in effect re-assemblesthe R, G and B components of the light beam and directs them togetherinto the projection lens 26 for projection onto the screen 24.

Each of the DMDs 32 comprises an array of reflective digital lightswitches (mirrors) that are integrated onto a silicon chip capable ofaddressing the switches individually. Each switch represents a singlepixel in the array and can be individually switched on or off inaccordance with digital information that is provided to the chip by anappropriate hardware and software controller. Each individual pixel ineach DMD is controlled to impart appropriate image information to thelight beam that is projected onto the screen 24.

However, since the projection system in accordance with the prior artbasically magnifies and projects original small images to be displayedon a large screen, it has a disadvantage that the image quality of theenlarged images necessarily degrades substantially compared with theoriginal images.

In addition, the DLP projection system in accordance with the prior arthas a problematic disadvantage that the image quality degrades due to anoptical illusion. The optical illusion, which is a phenomenon notphotographed but visible only to human eyes, degrades the image quality,when the images or human eyes move fast, for example, the rainbow colorsare seen on the spot of a high contrast ratio such as a black band on awhite background, or when grid patterns between respective pixels arecontrasted due to the fast eye movement.

SUMMARY OF THE INVENTION

The present invention is to resolve the above-mentioned problems. It isan object of the present invention to provide a precisely actuatingdevice formed in a one-piece unit capable of micro-rotating imageswithout loss of driving force or unnecessary clearance.

It is another object of the present invention to provide an imagetilting device capable of increasing the resolution by preciselyadjusting the angles of images.

It is another alternative object of the present invention to provide animage tilting device comprising a precisely actuating device, which isintegrated to precisely rotate the images without loss of driving forceor unnecessary clearance.

It is another alternative object of the present invention to provide aprojection system capable of improving the image quality, comprising animage tilting device capable of precisely adjusting the angles ofimages.

BRIEF DESCRIPTION OF THE DRAWINGS

The above objects and advantages of the present invention will becomemore apparent by describing in detail the preferred embodiments thereofwith reference to the attached drawings, in which:

FIG. 1 is a schematic view showing a projection system as known in theprior art.

FIG. 2 is a schematic sectional view showing a rotation device as knownin the prior art.

FIGS. 3 and 4 are schematic sectional views showing a preciselyactuating member in accordance with one aspect of the present invention.

FIG. 5 is a perspective view showing an image tilting device inaccordance with another aspect of the invention.

FIGS. 6 and 7 are schematic sectional views showing a preciselyactuating member applied to an image tilting device in accordance withanother aspect of the present invention.

FIG. 8 is a schematic view showing the mode of operation of theprecisely actuating member illustrated in FIGS. 6 and 7.

FIG. 9 is a schematic perspective view showing a modification of aprecisely actuating member applied to the image tilting device inaccordance with another aspect of the present invention.

FIG. 10 is a schematic sectional view showing a piezoelectric drivingelement applied to the image tilting device in accordance with anotheraspect of the present invention.

FIG. 11 is a schematic view showing the principle of operation of anelectromagnetic driving element applied to the image tilting device inaccordance with another aspect of the present invention.

FIGS. 12 and 13 are schematic views showing a variation on anelectromagnetic driving element applied to the image tilting device inaccordance with another aspect of the present invention.

FIG. 14 is a schematic sectional view showing another variation on theelectromagnetic driving element applied to the image tilting device inaccordance with another aspect of the present invention.

FIGS. 15 and 16 are schematic sectional views showing another variationon a precisely actuating member applied to the image tilting device inaccordance with another aspect of the present invention.

FIG. 17 is a schematic view showing a variation on a light pathconversion member applied to the image tilting device in accordance withanother aspect of the present invention.

FIG. 18 is a schematic view showing another variation on the light pathconversion member applied to the image tilting device in accordance withanother aspect of the present invention.

FIG. 19 is a schematic perspective view showing the image tilting deviceillustrated in FIG. 18.

FIG. 20 is a schematic view showing the principle of the light pathconversion member applied to the image tilting device illustrated inFIG. 18.

FIG. 21 is an exploded perspective view showing a variation on the imagetilting device in accordance with another aspect of the invention.

FIG. 22 is a perspective view showing the casing illustrated in FIG. 21.

FIGS. 23 and 24 are perspective views showing the precisely actuatingmember illustrated in FIG. 21.

FIGS. 25 and 26 are sectional views showing the precisely actuatingmember illustrated in FIG. 21.

FIG. 27 is a perspective view showing the pre-pressure springillustrated in FIG. 21.

FIGS. 28 and 29 are perspective views showing the frame illustrated inFIG. 21.

FIG. 30 is a perspective view showing the supporting member illustratedin FIG. 21.

FIG. 31 is a perspective view showing a fastening spring illustrated inFIG. 21.

FIG. 32 is a perspective assembly view showing a precisely actuatingmember and a light path conversion member of the image tilting device inaccordance with another aspect of the present invention.

FIG. 33 is a schematic view showing a first embodiment of the projectionsystem in accordance with another alternative aspect of the presentinvention.

FIGS. 34 and 35 are schematic views showing the principle of theincrease of the visible resolution of the projection system illustratedin FIG. 33.

FIG. 36 is a schematic view showing a second embodiment of theprojection system in accordance with another alternative aspect of thepresent invention.

FIGS. 37 and 38 are schematic views showing the principle of theincrease of the visible resolution of the projection system illustratedin FIG. 36.

FIG. 39 is a schematic view showing a third embodiment of the projectionsystem in accordance with another alternative aspect of the presentinvention.

FIGS. 40 and 41 are schematic views showing the principle of theincrease of the visible resolution of the projection system illustratedin FIG. 39.

FIGS. 42 to 51 are graphs showing a control wave generated by acontrol-wave generating device of the projection system illustrated inFIG. 39, and showing a variation of angles of the image tilting devicedriven by the control wave.

FIGS. 52 and 53 are schematic views showing the principle of theincrease of the visible resolution of the projection system illustratedin FIG. 39.

FIGS. 54 and 55 are graphs showing a control wave generated by thecontrol-wave generating device of the projection system illustrated inFIG. 39, and showing the variation of angles of the image tilting devicedriven by the control wave.

DETAILED DESCRIPTION OF THE INVENTION

In order to achieve the above-mentioned objects, in one aspect, thepresent invention provides a precisely actuating member, comprising apredetermined plate-shaped support portion; a hinge portion ofbottleneck structure extending vertically upward which is integratedwith the support to runs from one end to another end of the support; arotating portion which is integrated with the support portion and thehinge portion, is connected by the hinge portion to be disposed abovethe support portion, precisely reciprocates and rotates right and lefton the axis of the hinge portion.

In order to achieve the above-mentioned objects, in another aspect, thepresent invention provides an image tilting device comprising aprecisely actuating means which is housed within the casing and isintegrated so as to reciprocate precisely; a driving means whichdisposes contactably with the precisely actuating device to cause theprecisely actuating device to drive; and a light path conversion meanswhich is disposed above the precisely actuating member to convert alight path by a precise movement of the precisely actuating device.

The precisely actuating member comprises a predetermined plate-shapedsupport portion; a first hinge portion of bottleneck structure extendingvertically upward which runs from one end to another end of the supportportion; and a rotating portion which is connected by the hinge portionto be disposed above the support portion, and precisely reciprocates androtates right and left on the axis of the first hinge portion.

The precisely actuating member may further comprise an adjustment screwfor adjusting the initial angles of the support portion and the rotatingportion, a pre-pressure spring for controlling the pre-pressure of thesupport portion and the rotating portion, a plurality of balls for pointcontact.

The driving means may comprise a piezoelectric driving element and anelectromagnetic driving element.

The electromagnetic driving element may comprise a yoke of apredetermined shape for easily generating an electromagnetic force,which is attachable to the precisely actuating member; a permanentmagnet, which is attached to the yoke to form a magnetic field; anelectric wire arranged between the yoke and the permanent magnet to forma magnetic field with the permanent magnet.

The precisely actuating member comprising the electromagnetic drivingelement may comprise at least one connection portion, which contact withthe electromagnetic driving element to transmit the mechanical energy ofthe electromagnetic driving element to the precisely actuating member.

The image tilting device comprises a protrusion portion to support thelight path conversion means at one face, and may further comprise aframe of a predetermined height, and a supporting member which iscovered over the other side of the protrusion portion of the frame toprevent the light path conversion means interposed into the frame frombending.

The image tilting device may further comprise a frame of the light pathconversion means and a fastening spring for fixedly mounting thesupporting member above the precisely actuating device.

The image tilting device may further comprise a control wave generationmeans, which generates a control wave to control the movement of theprecisely actuating device.

In order to achieve the above-mentioned objects, another alternativeaspect of the present invention provides a projection system comprisinga light source generating a white light; a color processing means forimparting a predetermined color to the white light from the lightsource; a micro display means for displaying a predetermined image byuse of the light processed by the color processing means; at least oneprojection lens for projecting the images displayed on the micro displaymeans; an image tilt means which receives and precisely rotates theimages projected from the projection lens at a predetermined angle, andconverts the image projection path to transmit; and a screen forenlarging and displaying the images rotated precisely by the imagetilting device.

The projection system may further comprise an optical means forpicturizing the light processed by the color-processing device.

Hereinafter, the precisely actuating device, the image tilting device,and the projection system having them in accordance with the preferredaspect of the present invention will be described in detail withreference to the accompanying drawings. For it easier comprehension, thesame reference numbers were used for identical components in thedifferent figures wherever possible.

FIGS. 3 and 4 are schematic sectional views of the precisely actuatingmember of one aspect of the present invention.

Referring to FIGS. 3 and 4, the precisely actuating member 200 inaccordance with one aspect of the present invention comprises apredetermined plate-shaped support portion 210; a hinge portion 220 ofbottle neck structure extending vertically upward which is integratedwith said support portion and runs from one end to another of saidsupport portion 210; a rotating portion 230 integrated with the supportportion 210 and the hinge 220, which is connected by the hinge portion220 to be disposed above the support portion 210 and preciselyreciprocates and rotates right and left at the center of the hingeportion 220 in a reciprocating manner.

The support portion 210, the hinge portion 220 and the rotating portion230 are integrated by a same material, which is preferably formed ofaluminum or plastic having an elastic restoring force.

The support portion 210 is configured such that predeterminedplate-shaped members are overlapped in a layer structure, whereinanother hinge portion may be formed between the overlapped plate-shapedmembers.

The hinge portion 220 has a bottleneck structure formed in such a mannerthat both sides of a rectangular rod are trimmed symmetrically at apredetermined diameter. The portion of the thinnest thickness in thebottleneck structure is the shape of a thin plate, which acts as a platespring.

The rotating portion 230, which is a predetermined plate-shaped member,rotates precisely at the center of the hinge portion 220 when anexternal force F is applied to one end thereof as shown in FIG. 4.

Since the precisely actuating member 200 is integrated by a materialhaving an elastic restoring force, the rotating portion 230 preciselyrotates at the center of the hinge portion 220 when an external force isapplied by any driving element. At this time, the rotating portion 230precisely rotates continuously until the external force, which isapplied to the rotating portion 230 by the elasticity of the hingeportion 220, is counteracted to disappear or is removed.

A mirror 240 may be attached above the rotating portion 230. If anexternal force is applied to the precisely actuating member 200 attachedto the mirror 240, the mirror 240 attached to the rotating portion 230precisely rotates together, whereby the light reflecting on the mirror240 or a given image continuously rotate precisely according to thevariation of angle of the precisely-rotating mirror as shown by thearrows.

Referring to FIG. 5, the image tilting device 1000 in accordance withanother aspect of the present invention comprises a casing 1100; aprecisely actuating member 1200 which is housed within the casing 1100and is formed integrally so as to reciprocate precisely; a drivingmember (not shown) which contacts to the precisely actuating member 1200to cause the precisely actuating member to drive; and a light pathconversion member 1400 capable of converting a light path by the precisemovement of the precisely actuating member.

The casing 1100 is of a rectangular parallelepiped shape having apredetermined space therewithin with its upper portion open.

FIGS. 6 to 9 show the precisely actuating member 1200 applied to theimage tilting device in accordance with another aspect of the presentinvention.

FIGS. 6 to 9 are schematic views showing the precisely actuating member1200 a applied to the image tilting device in accordance with anotheraspect of the present invention.

Referring to FIGS. 6 to 9, the precisely actuating member 1200 acomprises a predetermined plate-shaped support portion 1210; a firsthinge portion 1220 of a bottleneck structure extending vertically upwardwhich runs from one end to another end of the support portion 1210; arotating portion 1230 which is connected by the hinge portion 1220 to bedisposed above the support portion 1210, and precisely reciprocates androtates right and left at the center of the first hinge portion 1220.

The support portion 1210, the first hinge portion 1220, and the rotatingportion 1230 are integrated by a same material, which is preferably madeof aluminum or plastic having an elastic restoring force.

The rotating portion 1230 rotates at the center of the first hingeportion 1220 when an external force F is applied to one end thereof asshown in FIG. 8.

The first hinge portion 1220 is of a bottleneck structure formed in sucha manner that both sides of a rectangular rod are symmetrically trimmedat a predetermined radius. The thinnest portion of the bottleneckstructure is of the shape of a thin plate, acting as a plate spring.

FIG. 8 shows the manner of operation of the plate spring 1221.

The plate spring 1221, if an external force F is applied to one sidethereof, is deformed in the direction of the force application generatea displacement Δd. The relationship between the external force F and thedisplacement Δd depends on the material, thickness, extent of the platespring 1221 and the point of application of the external force. If thedisplacement Δd is very small, the displacement Δd and the externalforce F have a proportional relation.

In addition, if the displacement Δd is within the range of elastic limitof the plate spring 1221, the plate spring 1221 is restored to itsoriginal state by its restoring force if the external force F isremoved.

The plate spring 1221 is deformable by a small force with respect to theexternal force F applied to both sides of the plate, but is not easilydeformed since the plate spring 1221 has a strong rigidity with respectto other directions.

Accordingly, due to the manner of operation of the plate spring 121, theprecisely actuating member 1200 a of FIGS. 6 and 7 can precisely rotateright and left at the center of the bottleneck structure of the firsthinge portion 1220 within the elastic limit of the first hinge portion1220.

Also, since the precisely actuating member 1200 a is integrated with asame material having an elastic restoring force, the uncertainty betweenthe external force applied and the displacement is minimized since thereis neither mechanical friction nor clearance unlike an assembledapparatus.

FIG. 9 is a schematic perspective view of a variation on a preciselyactuating member applied to the image tilting device in accordance withanother aspect of the present invention.

Referring to FIG. 9, the precisely actuating member 1200 b comprises apredetermined plate-shaped support portion 1210; a first hinge portion1220 of a bottleneck structure extending vertically upward which runsfrom one end to another end of the support portion 1210; and a rotatingportion 1230 which is connected by the hinge portion 1220 to be disposedabove the support portion 1210 and precisely and rotates right and leftat the center of the first hinge portion 1220.

The precisely actuating member 1200 b comprises a plurality of supportportions, wherein the plurality of support portions are composed of afirst support portion 1211 and a second support portion 1212, runs fromone end to another end, and are connected upwardly and downwardly by thesecond hinge portion 1222 of a bottleneck structure which extendsvertically upward. At this time, the second hinge portion 1222 isperpendicular to the first hinge portion 1220.

The first support portion 1211, the second support portion 1212, therotating portion 1230, the first hinge portion 1220 and the second hingeportion 1222 are integrated by the materials having an elastic restoringforce.

The precisely actuating member 1200 b may further comprise supportportion 1210 between respective plate-shaped members, an adjustmentscrew 1240 for adjusting the initial angle of the rotating portion 1230,and a pre-pressure spring not shown for adjusting the pre-pressure ofthe rotating portion 1230.

The first support portion 1211 and the second support portion 1212, asshown by the arrow, can precisely rotate at the center of the secondhinge portion 1222 connecting them. The rotating portion 1230 canprecisely rotate at the center of the first hinge portion above thesupport portion 1210.

At this time, the first hinge portion 1220 and the second portion hinge1222 is positioned perpendicularly to the respective length-direction,thereby adjusting the angle and rotation direction of each portion todifferent directions since the rotating portion 1230 of the preciselyactuating member 1200 b and the support portion 1210 precisely moves tothe orthogonal direction with respect to each other.

The first support portion 1211 and the second support portion 1212comprise at least one through hole 1213 for inserting the adjustmentscrew 1240 and/or the pre-pressure spring (not shown).

In addition, the first support portion 1211 and the second supportportion 1212 further comprise a through hole for inserting the drivingmember (not shown) for the movement of the precisely actuating member1200 b through the support portion 1210 so as to be contactable with therotating portion 1230.

The adjustment screw 1240 is inserted perpendicularly through thethrough hole 1213 to tilt the second support portion 1212 at apredetermined angle, thereby adjusting the angle of the precise rotationof the rotating portion 1230 positioned above the second support portion1212.

The adjustment screw 1240 may be positioned so as to be in contact withthe bottom surface of the second support portion 1212, or to be incontact with the bottom surface of the rotating portion 1230.

The pre-pressure spring (not shown) is positioned so as to be in contactwith the bottom surface of the rotating portion 1230 through the throughhole 1213 formed in the first support portion 1211, and the preciselyrotated rotating portion 1230 is returned to its original position bythe elastic restoring force of the pre-pressure spring as well as theelastic force of the first hinge portion 1220.

FIGS. 10 to 14 show the driving member applied to the image tiltingdevice 1000 in accordance with another aspect of the present invention.

The driving member of the image tilting device 1000 in accordance withanother aspect of the present invention, which is positioned between thesupport portion 1210 and the rotating portion 1230 of the preciselyactuating device 1200, is a device for precisely rotating the rotatingportion 1230 by contacting with the bottom surface of the rotatingportion 1230.

The driving member may comprise a piezoelectric driving element 1310,which converts an electric energy to a mechanical energy to drive theprecisely actuating member, and an electromagnetic driving element 1320,which generates a mechanical energy by a variation of magnetic field toprecisely rotate the precisely actuating member 1200.

Referring to FIG. 10, the piezoelectric driving element 1310 applied tothe image tilting device 1000 in accordance with another aspect of thepresent invention passes perpendicularly through the support 1210 to beinserted so that is in contact with the bottom surface of the rotatingportion 1230.

The piezoelectric driving element 1310 generates an oscillation ifvoltage is applied, its length increasing at about 10 μm if 100 voltsare applied. That is, the phenomenon is repeated that the length of thepiezoelectric driving element 1310 increases at about 10 μm by theoscillation and then returns to its original state.

Since the piezoelectric driving element 1310 is in contact with thebottom surface of the rotating portion 1230 of the precisely actuatingmember 1200 as shown in FIG. 10, the precise movement of thepiezoelectric driving element 1310 is transferred to the rotatingportion 1230, whereby the rotating portion 1230 can also rotateprecisely at the center of the hinge portion 1220 in a reciprocatingmanner.

The pre-pressure spring 1250 is positioned opposite to the piezoelectricdriving element 1310 at the center of the hinge portion 1220, servingfor the rotating portion 1230 rotated by the piezoelectric drivingelement 1310 to return to its original position.

The piezoelectric driving element 1310 may have a point contactstructure with the rotating portion 1230 of the precisely actuatingdevice 1200 in order to transmit the precise movement of thepiezoelectric driving element 1310 based on one point more accurately.For such point contact structure, a ball 1311 is positioned on top ofthe piezoelectric driving element 1310 so that the movement of thepiezoelectric driving element 1310 can be transmitted to the rotatingportion 1230 by the ball 1311 without being dispersed.

FIG. 11 shows the electromagnetic driving element 1320 applied to theimage tilting device in accordance with another aspect of the presentinvention.

Referring to FIG. 11, the electromagnetic driving element 1320 is of apredetermined shape for easily generating the electromagnetic force,comprising a yoke 1321 attachable to the precisely actuating member1200; a permanent magnet 1322 for forming an electric field by beingattached to the yoke 1321; and an electric wire 1323 positioned betweenthe yoke 1321 and the permanent magnet 1322 so as to form an electricfield with the permanent magnet 1322.

The yoke 1321 of the predetermined shape has a plurality of branchespositioned in parallel, being made of a metal-based material in order toform an electric field.

The yoke 1321 is provided with the permanent magnet 1322 on one side ofbranches, the upper and bottom surfaces of the permanent magnet 1322having opposite polarities. Due to this structure, an electric field isformed perpendicularly to the surface attaching the permanent magnet1322 between the branches of the yoke 1321 to which the permanent magnet1322 is attached.

The electric wire 1323 is positioned so as to pass between the branchesof the yoke 1321 to which the permanent magnet 1322 is attached. If anelectric current is applied to the electric wire 1323, a force isapplied to the arrow directions depending on the electric currentdirection by the interaction of the electric current and the permanentmagnet 1322.

If the electromagnetic driving element 1320 as described above isdisposed so as to be in contact with the rotating portion 1230 of theprecisely actuating member 1200, the force of the electromagneticdriving element 1320 is transmitted to the precisely actuating member1200 so that the rotating portion 1230 can precisely rotate in areciprocating manner.

The electromagnetic driving element 1320 may be used as a coil with theelectric wire 1323 wound around the branches of the yoke 1321 multipletimes.

FIGS. 12 to 14 illustrates variations of the electromagnetic drivingelement 1320 applied to the image tilting device 1000 in accordance withanother aspect of the present invention.

Referring to FIG. 12, the electromagnetic driving element is constructedsuch that the permanent magnet 1322 having different polarities at bothsides is attached to one side of the branch of the yoke 1321, and a coil1324 is wound multiple times around the opposite side of the branch towhich the permanent magnet 1322 is attached. The coil 1324 generates theforce proportional to the winding turns. In addition, the direction andmagnitude of the force applied to the coil 1324 can be adjusted byadjusting the direction and magnitude of the electric current flowingbetween one end and the other end of the coil 1324.

Referring to FIG. 13, the manner of the precise movement of theelectromagnetic driving element 1320 wound by the coil 1324 will bedescribed.

If an electric current is applied to the coil 1324 wound around the yoke1321, the coil 1324 is given a force in the length direction of thebranch of the yoke, perpendicular to the winding direction of the coil1324 according to the direction of the electric current applied.Accordingly, if the direction of electric current is adjusted, thedirection of the force applied to the coil 1324 changes. If suchphenomenon is rapidly repeated, the electromagnetic driving element 1320has such an effect as precisely oscillating.

The electromagnetic driving element 1320, as the variation of FIG. 14,may have more branches of the yoke 1321.

The electromagnetic driving element 1320 having three branches of theyoke 1321 is configured such that the permanent magnet 1322 is attachedto the branches positioned at both ends, and the coil 1324 is woundaround the branch positioned at the center, as shown in FIG. 12.

In addition, the electromagnetic driving element having more than fourbranches not shown is constructed in such a manner that a permanentmagnet is attached to the branches positioned at both ends, and the coilis wound around the remaining branches positioned at the center. If thepermanent magnet attached and the coils increase as the branchesincrease, the driving force of the electromagnetic driving elementincreases accordingly.

Such an electromagnetic driving element 1320 as described above isconstructed such that the branch is attached toward vertically upward tothe ends of the rotating portion 1230 of the precisely actuating member1200, like another variation of the precisely actuating member 1200applied to the image tilting device 1000 in accordance with anotheraspect of the present invention.

The precisely actuating member 1200 further comprises a connectionportion 1325, which is attached to the bottom surface of the rotatingportion 1230 to contact with the electromagnetic driving element 1320,in order to transmit the driving force of the electromagnetic drivingelement 1320 to the rotating portion 1230. The connection portion 1325is preferably formed integrally with the precisely actuating member1200.

If an electric current is applied to the electromagnetic driving element1320, the coil 1324 wound around the yoke 1321 is given a force in upand down directions, and then the force is transmitted through thecontacting connection portion 1325 to the rotating portion 1230 of theprecisely actuating member 1200. Thus, the precisely actuating member1200 can precisely rotate up and down in a reciprocating manner.

The electromagnetic driving element 1325, as shown in FIG. 15, may bepositioned at one end of the precisely actuating member 1200, and may bepositioned at both ends of the precisely actuating member 1200 in orderto make the driving force of the electromagnetic driving element bigger,as shown in FIG. 16. Due to the multiple connection portions as shown inFIG. 16, the driving force of the electromagnetic driving element 1320increases in proportion to the number of the electromagnetic drivingelement 1320.

Referring to FIGS. 17 to 20, there is shown the light path conversionmember applied to the image tilting device 1000 in accordance withanother aspect of the present invention.

The light path conversion member is a device, which can convert thelight path by the precisely reciprocating rotation of the preciselyactuating member 1200, may comprise a reflecting mirror 1410 or arefracting plate 1420.

Referring to FIG. 17, the reflecting mirror 1410 reflects an incidentlight to the direction indicated by the arrow shown in FIG. 17, and atthis time, the reflecting angle depends on the incident angle and thesmoothness of the reflecting mirror 1410, etc.

In addition, the reflecting angle is also influenced by the direction ofthe precise rotation of the precisely actuating member 1200 attachingthe reflecting mirror 1410. Accordingly, as the rotation axis A shown inFIG. 17, the reflecting angle at the time of rotating horizontally withrespect to the reflecting mirror 1410 becomes different from thereflecting angle at the time of rotating inclinedly at a predeterminedangle with respect to the reflecting mirror 1410. In general, if thereflecting mirror 1410 precisely rotates on the horizontal axis A, thereflected light moves precisely vertically at the center of the axis A.If the reflecting mirror 1410 precisely rotates on the inclined axis,the reflected light precisely moves vertically at the center of theinclined axis in an inclined manner.

Referring to FIGS. 18 and 19, the refracting plate 1420 transmits theincident light in the direction indicated by the arrow in FIG. 18, andat this time, the refracting angle depends on the material, angle, etc.of the refracting plate 1420.

In addition, since the refracting plate 1420 precisely reciprocates androtates with attachment to the precisely actuating member 1200 like thereflecting mirror 1410, the light path also changes according to therotation direction of the precisely actuating member 1200.

If the refracting plate 1420 is attached, since the refracting plate1420 should transmit the light, the precisely actuating member 1200 towhich the refracting plate attached preferably comprises a through hole1260 on its center as shown in FIG. 20.

Referring to FIG. 20, the manner of operation of the refracting plate1420 will be described.

To begin with, if a light is incident in the normal line direction ofthe refracting plate 1420, the light moves straight ahead, without beingrefracted, as indicated by the solid line shown in FIG. 20.

However, if the refracting plate 1420 is tilted at a predeterminedangle, since the light is tilted with respect to the incident surface ofthe refracting plate 1420, the light moves straight after beingrefracted at a predetermined angle depending on the refractive index ofthe refracting plate 1420, whereby the light path changes as indicatedby the dotted line in FIG. 20. In this manner, the refracting plate 1420is attached to the precisely actuating member 1200 for precise rotation,whereby the light moves to a predetermined direction in a reciprocatingmanner.

Accordingly, if the image tilting device 1000 precisely rotates on thehorizontal axis of rotation of the refracting plate 1420, the refractedlight precisely moves vertically on the rotation axis. If the imagetilting device 1000 precisely rotates on the inclined axis S, as shownin FIG. 18, the refracted light precisely moves vertically on theinclined axis (S) in a tilted manner.

Hereinafter, referring to FIGS. 21 to 32, a variation of the imagetilting device 1000 in accordance with another aspect of the presentinvention will be described in detail.

Referring to FIG. 21, the image tilting device 1000 comprises a casing1100; a precisely actuating member 1200 which is housed within thecasing 1100 and formed integrally so as to precisely rotate in areciprocating manner; a driving member 1300 which contacts to theprecisely actuating member 1200 to cause the precisely actuating memberto drive; and a light path conversion member 1400 which is positionedabove the precisely actuating member 1200 to convert the light path bythe precise movement.

The image tilting device 1000 further comprises the precisely actuatingmember 1200, an adjustment screw 1240 for adjusting the initial angle ofthe support portion 1210 and the rotating portion 1230, a fasteningscrew 1241 for fastening the precisely actuating member 1200 on thecasing 1100, a pre-pressure spring 1250 for adjusting the pre-pressureof the support portion 1210 and the rotating portion 1230, and aplurality of balls 1311 for point contact.

The image tilting device 1000 also comprises a protrusion portion 1431at one side to support the light path conversion member 1400, and maycomprise a frame 1430 of a predetermined height; and a supporting member1440 which is covered on the other side of the protrusion portion 1431of the frame 1430 to prevent the light path conversion member 1400inserted into the frame 1430 from bending.

The frame 1430 of the light path conversion member 1400 and theprecisely actuating member 1200 comprise a projection and a groove forassembly, respectively, and may further comprise a fastening spring 1450for fixedly mounting the frame 1430 and the supporting member 1440 onthe precisely actuating member 1200.

Referring to FIG. 22, the casing 1100 is of a rectangular parallelepipedshape having a predetermined space therewithin with its upper portionopen. The bottom surface of the casing 1100 comprises a plurality ofscrew holes 1110 for fastening the precisely actuating member 1200, andthe sidewalls of the casing 1100 comprise a plurality of verticalgrooves 1120 corresponding to the shape of the precisely actuatingmember 1200.

Referring to FIGS. 23 and 24, the precisely actuating member 1200 iscomposed of the first support portion 1211, the second support portion1212, and the first hinge portion 1220, the second hinge portion 1222and the rotating portion 1230.

The first support portion 1211 is of a plate shape, whose both ends areprojected outward in a semi-circular shape, and the semi-circularprojection 1215 comprises a first through hole 1213 for inserting ascrew. The bottom surface of the first support portion 1211 bends inwardto form a step, wherein the step comprises a second through hole 1214and a third through hole 1216 of length direction in parallel with eachother on its center. Fourth through holes to insert other screws arealso disposed between both ends of the second and the thirds throughholes 1214 and 1216.

The second support portion 1212 is connected by the second hinge portion1222 to the first support portion 1211 to be disposed above the firsthinge portion 1211, both ends of the second support portion 1222 havinga groove 1218 formed at a regular width.

The rotating portion 1230 is connected to the second support portion1212 by the first hinge portion 1220 to be disposed above the secondsupport portion, each edge of the rotating portion 1230 extendingvertically upward to form a rim 1231. The rim 1231 comprises a pluralityof grooves 1232s on its opposite positions partially.

Both ends of the rotating portion 1230 have a rectangular extension 1233which partially extends outward, the rectangular extension 1233comprising a cylindrical projection 1234 projecting vertically upward.

The upper surface of the rotating portion 1230 further comprises aplurality of grooves 1235 of a rectangular shape, which are arranged inrows and columns.

Referring to FIGS. 25 and 26, the first hinge portion 1220 supports therotating portion 1230, which precisely rotates in reality, in the samemanner as the plate spring, and the second hinge portion 1222 is toadjust the precise rotation of the second support portion 1212, thefirst hinge portion 1220 and the second hinge portion 1222 beingperpendicular to each other in the length direction.

Since the rotation direction of the rotating portion 1230 and the secondsupport portion 1212 is adjustable based on different axes, due to theperpendicular structure of the first hinge portion 1220 and the secondhinge portion 1222, the rotation direction of the precisely actuatingmember is adjustable in a variety of manners.

Referring to FIG. 26, the second hinge portion 1222 is cut by a lengthequivalent to the width of the pre-pressure spring or the driving memberin order to insert the pre-pressure spring or the driving member fromthe bottom of the first support portion 1211 or to be in contact withthe second support portion 1212 or the rotating portion 1230. Since thepre-pressure spring or the driving member can be inserted through thefirst support portion 1211 due to this structure, the initial angle ofthe second support portion can be adjusted, and also transmit themovement of the driving member to the rotating portion 1230.

FIG. 27 illustrates the pre-pressure spring 1250, which is inserted intothe precisely actuating member 1200 to adjust the pre-pressure.

The pre-pressure spring 1250 comprises a through hole 1251 in the middleof a plate shaped member having a predetermined thickness, which isdivided into an elastic portion 1252 providing an elastic restoringforce and a support portion 1253 supporting the elastic portion 1252.The elastic portion 1252 is of a narrower band than other portions,providing an elastic restoring force in the same manner as the platespring.

The elastic portion 1252 comprises a projection 1254 extendingvertically upward in the middle, wherein the projection 1254 is placedto be contactable with the bottom surface of the rotating portion 1230,and transmits the elastic restoring force of the pre-pressure spring1250 when the rotating portion 1230 rotates precisely.

FIGS. 28 and 29 show the frame 1430 for supporting the light pathconversion member 1400.

The upper surface of the frame 1430 is of a shape capable of coveringand supporting the light path conversion member 1400, comprising aprotrusion portion 1431 for locking the light path conversion member1400 inside the frame 1230 so as not to being deviated.

The frame 1430 is provided with square projections 1432 for assemblingwith the precisely actuating member 1200 at both ends, and a pluralityof connecting projections 1433 for attaching a support member, whichwill be explained later, at the other, both ends.

The square projection 1432 comprises a groove 1434 for attaching afastening spring, which will be explained later, inside the uppersurface to increase the assembly accuracy, and a groove 1435 of a shapecorresponding to the cylindrical projection 1234 of the preciselyactuating member 1200 for assembling with the precisely actuating member1200, at the bottom surface.

The frame 1430 as described above is of a shape matching up with therotating portion 1230 of the precisely actuating member 1200, whichallows the light path conversion member 1400 to be securely attached ontop of the rotating portion 1230 due to respective projections 1432,1433 and grooves 1434, 1435 for assembly.

Referring to FIG. 32, there will be explained a supporting member 1440which covers the other side of the protrusion portion 1431 of the frame1430 to prevent the light path conversion member 1400 from bending.

The supporting member 1440 is attached to the bottom of the light pathconversion member 1400 to support the light path conversion member 1400,having a predetermined plate shape capable of being locked tightly onthe light path conversion member 1400. The plate-shaped portioncomprises four legs 1441 which, after being assembled with the frame1430, is safely reached to the rectangular groove 1235 formed at therotating portion 1230 of the precisely actuating member 1200.

The legs 1441, after extending downward at a predetermined inclinationat the plate-shaped portion, extend horizontally again so as to behorizontally secured into the rectangular groove 1235.

Both ends of the supporting member 1440 comprises a guide 1442 bentvertically upward which extends to the plate-shaped member so as tomatch with the binding projection 1433 provided on both ends of theframe 1430, which prevents the supporting member 1440 from beingdeviated by the elastic force.

The supporting member 1440 is configured such that the surface contactregion of the light path conversion member 1400 with the supportingmember 1440 is opposite to the surface contact region of the frame 1430with the light path conversion member 1400, and that the bending momentapplied to the light path conversion member 1400 becomes to minimize sothat the line of action of the contact force can become in a straightline.

In addition, the surface where the supporting member 1440 and the frame1430 contact with the light path conversion member 1400 is of a shapesurrounding the outer perimeter of the light path conversion member1400, which minimizes the stress concentration.

Referring to FIG. 31, there will be explained a fastening spring 1450for securing fixedly the frame 1430 and the supporting member 1440 ontop of the precisely actuating member 1200.

The fastening spring 1450 being a plate spring is of a shape verticallybent to make both ends horizontal, one end being then vertically bentinward again, and the other end being bent inward so as to have apredetermined inclination and thereafter being vertically bent withrespect to the inclination.

The bent, both ends of the fastening spring 1450 can be widened andrestored by the elastic force. The inward-bent structure of both ends isto secure the frame 1430 attaching the light path conversion member 1400and the supporting member 1440 on the precisely actuating member 1200.

Referring to FIG. 32, there will be explained the assembly process ofthe precisely actuating member 1200 and the light path conversion member1400.

First, the perimeter of the light path conversion member 1400 is coveredby the frame 1430 to support the light path conversion member 1400, andthen the supporting member 1440 is covered the frame 1400 from thebottom. The supporting member 1440 is locked to the binding projection1433 of the frame 1430 by the guides 1442 provided with both ends,thereby supporting the light path conversion member 1400 securely.

The light path conversion member 1400 assembled with the frame 1430 andthe supporting member 1440 as described above is placed on the rotatingportion 1230 of the precisely actuating member 1200. At this time, sincethe rotating portion 1230 is configured such that the middle is closed,the light path conversion member applied to the variation of the imagetilting device in accordance with another aspect of the presentinvention is preferably the reflecting mirror 1410.

The light path conversion member 1400 as assembled above is placed onthe rotating portion 1230, and, at this time, the guide 1442 of thesupporting member 1440 is locked to the groove 1232 which is partiallyformed at the perimeter of the rotating portion 1230, and is securelyassembled with the matching structure provided with both ends of theframe 1430 and the rotating portion 1230. Thereafter, the fasteningspring 1450 is fastened to both ends provided with the matchingstructure so that the precisely actuating member 1200 and the light pathconversion member 1400 are fixedly secured in order not to break awayfrom each other.

The precisely actuating member 1200 and the light path conversion member1400 assembled as above insert the driving member 1300 and thepre-pressure spring 1250 from the bottom of the support portion 1210 asshown in FIG. 21.

The driving member 1300 and the pre-pressure spring 1250 also insert theball 1311 into the portion where the precisely actuating member 1210 isinserted to contact the bottom surface of the rotating portion 1230, forthe point contact with the precisely actuating member 1200. The ball1311, which is additionally provided for the point contact, may form theshapes of the driving member 1300 and the pre-pressure spring 1250 intoa circular shape.

The members assembled as above are housed within the casing 1100 to besecured to the screw hole 1110 of the casing 1100 by the fastening screw1241.

The image tilting device 1000 in accordance with another aspect of thepresent invention assembled as described above comprises a plurality ofadjustment screws 1240 which are inserted into the screw holes formed onthe casing 1100, in order to adjust the initial angle of the supportportion 1210 of the precisely actuating member 1200. A plurality ofballs 1311 may be positioned on the adjustment screws 1240 for the pointcontact with the precisely actuating member 1200. The ball 1311 isadditionally provided for the point contact, but may form the end shapeof the adjustment screw into a sphere shape.

The projection system 2000 having the image tilting device 1000 inaccordance with another aspect of the present invention will bedescribed with reference to the accompanying drawings hereinbelow. Theprojection system 2000 in accordance with another aspect of the presentinvention may comprise the image tilting device 1000 in accordance withanother aspect of the present invention.

Referring to FIGS. 33 to 55, there will be explained the projectionsystem 2000 in accordance with another alternative aspect of the presentinvention.

The projection system 2000 in accordance with another aspect of thepresent invention comprises a light source 2100 generating a whitelight; a color-processing device 2200 for imparting a predeterminedcolor to the white light from the light source 2100; a micro displaydevice 2300 which displays a predetermined image by using the lightprocessed by the color-processing device 2200; at least one projectionlens 2400 which projects an image displayed on the micro display device2300; an image tilting device 1000 which receives an image of theprojection lens 2400 and precisely rotates the image at a predeterminedangle, and converts the path thereof to be transmitted; and a screen2500 which magnifies the image which is precisely rotated by the imagetilting device 1000.

A lamp light source generating a white light may be used as the lightsource 2100.

The color-processing device 2200 is a color filter for separating thewhite light of the light source into red, green, and blue falling undertrichromatic colors, which arranges filters for respective colorsadjacently to respectively and applies a signal corresponding torespective colors to control the illumination, thereby expressingvarious colors.

The micro display device 2300 is to display an image on the micro panelby using the color displayed by the color-processing device 2200. Areflective, micro display is used in the projection system in accordancewith another alternative aspect of the present invention.

The projection lens 2400 may comprise a first projection lens 2410,which projects an image displayed by the micro display device 2300 foradjusting an angle, and a second projection lens 2420, which magnifiesand displays an image of which the angle is adjusted.

The image tilting device 1000, which receives an image of the projectionlens 2410, rotates precisely the image at a predetermined angle, andconverts the path of the image for transmission, may use a reflectivemirror 1410, a refractive plate 1420, etc. to convert the path of image.The projection system 2000 in accordance with another alternative aspectof the present invention preferably comprises the image tilting device1000 in accordance with another aspect of the present invention.

The image tilting device 1000 may precisely rotates so that an imagedisplayed on the screen through the light path conversion member 1400can move to the diagonal axis direction of the screen 2500 in areciprocating manner.

The image tilting device 1000 may also precisely rotates on the diagonalaxis of the light path conversion member 1400.

FIG. 33 illustrates a first embodiment of the projection system inaccordance with another alternative aspect of the present invention.

In the projection system 2000 as shown in FIG. 33, the white lightgenerated from the light source 2100 has a light synchronized with theimage displayed on the micro display device 2300 as passing through thecolor-processing device 2200. The image displayed on the micro displaydevice 2300, after passing through the first projection lens 2410, isreflected by the image tilting device 1000, to which the reflectivemirror 1410 is attached, to be then magnified on the screen 2500 by thesecond projection lens 2420.

The reflective mirror 1410 is attached to the image tilting device 1000to rotate by the rotation of the image tilting device 1000. At thistime, since the image tilting device 1000 may rotate on the longitudinalor horizontal axis thereof, or may rotate on the oblique axis of apredetermined angle, the rotation direction of the reflective mirror1410 attached thereto changes together.

As illustrated in FIG. 33, an image which rotates on the horizontalrotation axis H of the image tilting device 1000 moves precisely up anddown the screen 2500 in the same direction as indicated by the arrow onthe screen 2500.

Referring to FIGS. 34 and 35, the principle of the increase ofresolution when the image moves precisely up and down the screen 2500 asdescribed above will be explained.

When the image tilting device 1000 is at the initial position, thepixels of the image projected on the screen 2500 are shown in FIG. 34-a.If the image tilting device 1000 rotates at a precise angle, the pixelsof the image projected on the screen 2500 move precisely on the screen2500 overall to become an image like FIG. 34-b. If the images of suchtwo states are periodically displayed on the screen 2500 at less than0.03 second intervals, that is, if the image tilting device 1000 doesregular periodic motion at a high speed, the human eye recognizes acombination image of FIG. 35 that the image of FIG. 34-a and that of34-b are overlapped.

In this case, if the length of the movement of the images by the imagetilting device 1000 is p/2 which is half the vertical height p of theoriginal pixel size, the image of FIG. 34-a and the image of FIG. 34-boverlap by a half pixel, the human eye recognizes the pixels of FIG. 35which got smaller by a half, whereby the visible resolution increases.

FIG. 36 illustrates a second embodiment of the projection system 2000 inaccordance with another alternative aspect of the present invention.

In the projection system 2000 as shown, the white light generated fromthe light source 2100 has a light of the color synchronized with theimage displayed on the micro display device 2300 as it passes throughthe color-processing device 2200. The image displayed on the microdisplay device 2300, after passing through the first projection lens2410, is refracted and transmitted at a predetermined angle by the imagetilting device 1000, to which the refraction plate 1420 is attached, tobe then magnified on the screen 2500 by the second projection lens 2420.

The refraction plate 1420 is attached to the image tilting device 1000to be rotated by the rotational movement of the image tilting device1000. At this time, since the image tilting device 1000 may rotate onthe vertical or horizontal axis of the image tilting device 1000, or mayrotate on the oblique axis (S) of a predetermined angle, the rotationdirection of the refractive plate 1420 attached thereto changesaccordingly.

The image which rotates on the oblique axis (S) of the image tiltingdevice, as shown in FIG. 36, moves precisely in the oblique direction ofthe screen 2500, which is the same direction as indicated by the arrowon the screen 2500.

In FIGS. 37 and 38, there will be explained the principle of theincrease of resolution when the image moves precisely in the obliquedirection of the screen 2500, as described above.

When the image tilting device 1000 is at the initial position, thepixels of the image projected on the screen 2500 are shown in FIG. 37-a.When the image tilting device 1000 rotates at a precise angle, thepixels of the image projected on the screen 2500 overall move preciselyon the screen 2500 to become an image like FIG. 37-b. If the images ofsuch two states are periodically displayed on the screen 2500 at lessthan 0.03 second intervals, that is, if the image tilting device 1000does regular periodic motion at a high speed, the human eye recognizes acombination image of FIG. 38 that FIGS. 37-a and 37-b are seenoverlapping.

That is, if the image tilting device 1000 moves precisely like the imageof FIG. 37-b which moves vertically or horizontally by a half pixel p/2with respect to the image of FIG. 37-1, the human eye recognizes theimage which became smaller by a quarter like FIG. 38, whereby thevisible resolution increases four times.

FIG. 39 illustrates a third embodiment of the projection system inaccordance with another alternative aspect of the present invention.

The projection system 2000 comprises a light source 2100 generating awhite light; a color-processing device 2200 for imparting apredetermined color to the white light from the light source 2100; amicro display device 2300 which displays a predetermined image by usingthe light processed by the color-processing device 2200; at least oneprojection lens 2400 which projects an image displayed on the microdisplay device 2300; an image tilting device 1000 which receives animage of the projection lens 2400 and rotates precisely the image at apredetermined angle, and converts the path of the image to transmit; anda screen 2500 which magnifies the image which is precisely rotated bythe image tilting device 1000.

The projection system 2000 further comprises a control-wave generatingdevice 2600, which generates a control-wave for driving the imagetilting device 1000.

The projection system 2000 may further comprise an optical device 2700for imaging the light processed by the color-processing device 2200.

The optical device 2700 concentrates the light on the micro displaydevice 2300 in such a form that the light can be effectively incident onthe micro display device 2300.

In the projection system 2000, the micro display device 2300 may bearranged so that the pixel is obliquely illuminated on the screen 2500,which will be explained later with reference to FIGS. 40 and 41.

The micro display device 2300 is arranged such that the pixel is placedin the oblique direction as shown in FIG. 40-a. Accordingly, when theimage tilting device 1000 is at the initial position, the imageprojected on the screen 2500 is shown as the FIG. 40-a. When the imagetilting device 1000 rotates at a precise angle, the image projected onthe screen 2500 overall moves precisely on the screen 2500 to become animage like FIG. 40-b. If the images of such two states are periodicallyand repeatedly displayed on the screen 2500 at less than 0.03 secondintervals, that is, if the image tilting device 1000 moves at a highspeed in a regular periodic manner, the human eye recognizes acombination image of FIG. 41 which FIGS. 40-a and 40-b are seenoverlapping.

In this case, if the movement of the images by the image tilting device1000 is, for example, p/2 which is half the diagonal height p of theoriginal pixel size, the image of FIG. 40-a and the image of FIG. 40-boverlap by a half pixel above and below. At this time, the variation ofthe actual height is merely a half the original pixel size, but thehuman eye recognizes the pixels of FIG. 41, which gets smaller to aquarter of its original size since the pixel of the micro display device2300 is arranged in the diagonal direction. Thus, the visible resolutionincreases four times.

The projection system 2000 in accordance with another alternative aspectof the present invention further comprises a control-wave generatingdevice 2600, which generates a control wave for controlling the movementof the image tilting device 1000.

The control-wave generating device 2600 generates a control wave havingtwo values for periodically reciprocating the image tilting device 1000during a regular time period between two predetermined angularpositions.

The control-wave generating device 2600 generates a resultant wave ofsuch a shape that the horizontal, flat portion of a square wave islinked with the rising portion or the falling portion of the sine wave,in order to reduce the residual oscillation of the control-wave signal.

The flat portion of the resultant wave is composed of the upper flatportion and the bottom flat portion, each flat portion having at leastone step.

The at least one step is configured such that the upper flat portion issymmetrical to the bottom flat portion.

Referring to FIGS. 42 to 55, there is explained the control-wavegenerating device 2600 applied to the projection system in accordancewith another alternative aspect of the present invention.

In order to position periodically the image tilting device 1000 at thetwo predetermined angular positions during a regular time period, thecontrol-wave generating device 2600, as shown in FIG. 42, generates asquare wave control signal defined by two predetermined voltages(V_(high), V_(low)). Accordingly, the image tilting device 1000 does anangular movement following the square wave control signal.

FIG. 43 is a graph illustrating the rotation angle of the image tiltingdevice 1000, which does the angular movement following the square wavecontrol signal. As shown in FIG. 43, if the square wave control signalis applied to the image tilting device 1000, the angular movement does afeature having a residual oscillation. The residual oscillation isgenerated by a rapid control input, i.e., impulsive force, due to arapidly changing portion of the square wave control signal.

As shown in FIG. 44, when the sine wave-shaped control signal defined bythe two predetermined voltages (V_(high), V_(low)) is applied to theimage tilting device 1000 in order to reduce the residual oscillationdue to the square wave input signal as described above, the imagetilting device 1000 exhibits a sine wave-shaped angular movementfollowing the sine wave driving signal, as shown in FIG. 45.Accordingly, the image tilting device 1000 in accordance with anotheraspect of the present invention exhibits the feature of following thesine wave.

The following movement happens when the frequency of the sine wavecontrol signal is less than the natural frequency of the image tiltingdevice 1000, which is the case for all mechanical driving systems.

Referring to FIGS. 46 to 49, in order to use the characteristic offollowing sine wave in a periodical rotation movement having two angularstates, the principle of generating a control wave of the control-wavegenerating device 2600 will be explained.

Referring to FIGS. 46 and 47, in order to regularly position therotation angles of the image tilting device 1000 at the two anglepositions, the curve portion corresponding to the rising portion 2610 orthe falling portion 2620 of the sine wave is positioned between the twoflat portions of the square wave having the two flat portions 2630 and2640.

FIGS. 48 and 49 show the control wave when the image tilting device 1000is actuated by the control signal, and the angle output of the imagetilting device 1000.

The control wave has two flat portions 2630 and 2640, but can reducesignificantly the residual oscillation of the image tilting device 1000generated when actuated only by the square wave, by substituting therapidly changing portion of the square wave, where the two values changerapidly, with the rising portion 2610 or the falling portion 2620 of thesine wave. Accordingly, the image tilting device 1000 also follows thesine wave to precisely rotate in a reciprocating manner so as to have apredetermined angular variation value as shown in FIG. 49.

When the projection system 2000 in accordance with another alternativeaspect of the present invention is driven by actuating the image tiltingdevice 1000 by the control-wave generating device, the image displayedon the screen 2500 is seen as an image having an increased visibleresolution due to the optical illusion of the human eye as shown in FIG.38 or 41.

However, when people watch the image having an increased visibleresolution, if the direction of glance changes swiftly, or if the humaneye blinks or a sudden change happens such as a rapid change of theimage displayed, a phenomenon like a camera shutter occurs to the humaneye function. Thus, one of the two original images forming the increasedvisible resolution image in FIG. 38 or 41 is directly seen. In otherwords, the optical illusion disappears, an image of low resolution comesin sight, and the pixel grid is seen.

The control-wave generating device 2600 applied to the projection systemin accordance with another alternative aspect of the present inventiongenerates a control wave having at least one step in order to reduce theresolution degradation.

Referring to FIGS. 50 to 55, the control wave has two flat portionshaving a same voltage displacement (Δv/2) above and below the originalvoltage (V_(high)). The two flat portions are maintained for the sametime period, respectively, which are linked by the sine wave as shown inFIG. 48. The bottom flat portion 2640 has two different, flat portionslike the upper flat portion 2630, which are symmetrical to each other atthe upper flat portion 2630 and the bottom flat portion 2640.

Due to the control wave as described above, the image tilting device1000, as shown in FIG. 51, rotates precisely in a reciprocating mannerat an angular displacement modulated by Δθ/2.

Accordingly, due to the modulated angular displacement, the imagedisplayed on the screen 3500 during the time period when the imagetilting device 1000 has the displacement of Δθ at the flat portions 2630and 2640, has the displacement ΔD corresponding to Δθ as shown in FIG.52.

That is, since due to the step of the upper flat portion 2630 of themodulated angular displacement, the images corresponding to each step isseen overlapping, whereby the grid looks blurry due to the averageperception of the human eye, as shown in FIG. 53. Accordingly, it isperceived that the image quality is good, since the grid is lessemphasized.

FIG. 54 shows a modulated control wave having three steps at respectiveflat portions 2630 and 2640, and FIG. 55 shows a modulated control wavehaving four steps at respective flat portions 2630 and 2640.

Each step has the same voltage displacement (Δv/2) high and low theoriginal voltages (V_(high), V_(low)), and is maintained during the sametime period, respectively.

The precisely actuating member and the image tilting device inaccordance with a preferred aspect of the present invention, and theoperation and effects of the projection system will be explainedhereinbelow.

The precisely actuating member in accordance with one aspect of thepresent invention comprises a predetermined plate-shaped supportportion, which is integrated by a material having an elastic restoringforce, a predetermined plate-shaped rotating portion which disposed onthe support portion, and a hinge portion of bottleneck structure whichconnects the support portion and the rotating portion and acts as aplate spring.

If any external force is applied to the rotating portion, the rotationportion precisely rotates periodically on the axis of the hinge portiondue to its elasticity until it is returned to its original position. Atthis time, a mirror attached on the upper surface of the rotatingportion also rotates precisely, whereby a light or an image reflected onthe mirror can rotate precisely.

Since the precisely actuating member is integrated, unnecessary recessesare reduced relative to a precisely actuating member which is assembledwith a plurality of members, and the rotation accuracy also increasessince it rotates precisely only by the elastic restoring force of thematerial itself.

The image tilting device in accordance with another aspect of thepresent invention houses the precisely actuating member integratedwithin the casing, and the driving member, which contacts to theprecisely actuating member to cause the movement of the preciselyactuating member.

The precisely actuating member is composed of a plurality of supportportions, rotating portion, and a plurality of hinge portions, wherein apiezoelectric driving element or an electromagnetic driving element isarranged between the support portion and the rotating portion. Thelength of the driving elements changes if voltage is applied, and suchmechanical motion is transmitted to the rotating portion of theprecisely actuating member which contacts with the driving elements.Accordingly, the rotating portion moves precisely.

At this time, since the hinge portion integrated between the supportportions elastically supports the rotating portion, the rotating portionprecisely rotates on the axis of the hinge in a reciprocating manner.The precisely actuating member can precisely rotate without loss of thedriving force, since it is integrated with the support portions,rotating portion, and hinge portions. In addition, the light pathconversion member attached to the upper surface of the rotating portionreciprocates and rotates according to the movement of the rotatingportion.

The projection system in accordance with another alternative aspect ofthe present invention comprises a light source generating a white light;a color-processing device for imparting a predetermined color to thewhite light from the light source; a micro display device for displayinga predetermined images by use of the light processed by thecolor-processing device; at least one projection lens for projecting theimages displayed on the micro display device; an image tilting devicefor receiving and rotating precisely the images of the projection lensat a predetermined angle to convert the path for transfer; and a screenfor magnifying to display the images rotated precisely by the imagetilting device. The preferred image tilting device uses the imagetilting device in accordance with another aspect of the presentinvention.

The projection system comprising the image tilting device in accordancewith another aspect as described above transmits the image passingthrough the light source, the color-processing device, the micro displaydevice, and the projection lens to the image tilting device.

Since the image tilting device reciprocates and rotates minutely ifvoltage is applied, the image transmitted to the image tilting devicealso precisely moves obliquely to a predetermined direction by the lightpath conversion member attached to the image tilting device.

At this time, the projection system in accordance with anotheralternative aspect of the present invention may make the imagereciprocate in the diagonal direction of the screen by positioning thepixel of the micro display device obliquely with respect to theprojection surface of the screen. In addition, the image tilting deviceitself reciprocates and rotates in the oblique direction of the screen,thereby allowing the image to precisely move obliquely to the projectionsurface of the screen.

If the image precisely reciprocates and rotates obliquely as describedabove, the displacement occurs up and down the pixel due to the obliquemovement direction, so that the upper and lower sides of the pixel lookoverlapping. Accordingly, the boundary with respect to every sides ofthe pixel becomes blurry. As a result, the resolution increases due tothe optical illusion.

The projection system in accordance with another alternative aspect ofthe present invention further comprises a control-wave generatingdevice, thereby increasing the visible resolution.

In general, when an image of increased visible resolution is seen by anoptical illusion, if eyesight changes rapidly, a phenomenon as ifpressing a camera shutter takes place, whereby the image looks as if itis still. Then, the pixel grid of the screen is visually perceiveddirectly, so the resolution looks degraded.

To resolve this problem, the control-wave generating device generates amodulation control wave having a predetermined step at the flat portionof the control wave to precisely and rotates the precisely actuatingmember so as to following the modulation control wave. Then, the images,which moved by the displacement corresponding to the value of each step,look overlapping, whereby the image quality is perceived as good sincethe grid of the pixel is less emphasized.

Hereinabove, the image tilting device in accordance with another aspectof the present invention, and the projection system having it wereexplained. However, the image tilting device may be applied to lightscanning systems, etc. which are actuated to form patterns on asemiconductor wafer, in addition to the projection system by using theprinciple of the precisely reciprocating rotation of the driving memberor the control-wave generating device.

Since the precisely actuating member in accordance with one aspect ofthe present invention can rotate precisely by the elastic force withoutunnecessary movement since it is integrated, it can precisely rotate animage.

Since the image tilting device in accordance with another aspect of thepresent invention comprises an integrated precisely actuating member,thereby minimizing unwanted movements and rotating precisely an imagewithout loss of the driving force.

In addition, the projection system in accordance with anotheralternative aspect of the present invention can reduce the volume of thesystem itself by using the image tilting device in accordance withanother aspect of the present invention, and can increase the imagequality even with the existing display panel in use by adjusting freelythe rotation angle of the image tilting device rotating precisely.

While this invention has been shown and described with references topreferred aspects thereof, it will be understood by those skilled in theart that various changes in form and details may be made therein withoutdeparting from the scope of the invention encompassed by the appendedclaims.

1. A precisely actuating member comprising: a predetermined plate-shapedsupport portion; a hinge portion of bottleneck structure extendingvertically upward, which is integrated with said support portion, andruns from one end to the other end of said support portion; and arotating portion, which is integrated with said support portion and saidhinge portion, is connected by said hinge portion to be disposed on saidsupport portion, and reciprocates and rotates precisely right and lefton the axis of said hinge portion.
 2. The precisely actuating memberaccording to claim 1, wherein a mirror is attached to said rotatingportion.
 3. An image tilting device comprising: a casing; a preciselyactuating means which is housed within said casing and is integratedtherewith so as to precisely reciprocate; a driving means which contactsto said precisely actuating member for the movement thereof; and a lightpath conversion means, which is placed on said precisely actuating meansto be able to convert a light path by a precise movement.
 4. The imagetilting device according to claim 3, wherein said precisely actuatingmeans comprises: a predetermined plate-shaped support portion; a firsthinge portion of bottleneck structure extending vertically upward, whichruns from one end to the other end of said support portion; and arotating portion, which is connected by said first hinge portion to bedisposed on said support portion, and precisely reciprocates and rotatesright and left on the axis of said first hinge portion.
 5. The imagetilting device according to claim 4, wherein said support portion isplural.
 6. The image tilting device according to claim 5, wherein saidplurality of support portion is connected up and down a second hingeportion of bottleneck structure extending vertically upward which runsfrom one end to the other end of said support portion.
 7. The imagetilting device according to claim 6, wherein said second hinge portionis perpendicular to said first hinge portion.
 8. The image tiltingdevice according to claim 4, wherein said precisely actuating meansfurther comprises an adjustment screw for adjusting the initial angle ofthe support portion and the rotating portion.
 9. The image tiltingdevice according to claim 4, wherein said precisely actuating meansfurther comprises a pre-pressure spring for adjusting the pre-pressureof said support portion and said rotating portion.
 10. The image tiltingdevice according to claim 4, wherein said driving means preciselyrotates the rotating portion by contacting with the rotating portion ofthe precisely actuating member.
 11. The image tilting device accordingto claim 10, wherein said driving means is a piezoelectric drivingelement which converts an electric energy into a mechanical energy todrive said precisely actuating member.
 12. The image tilting deviceaccording to claim 11, wherein said piezoelectric driving element pointcontacts with said precisely actuating member.
 13. The image tiltingdevice according to claim 12, wherein said precisely actuating meansfurther comprises a plurality of balls for point contacts.
 14. The imagetilting device according to claim 10, wherein said driving means is anelectromagnetic driving element which generates a mechanical energy by avariation of magnetic field to precisely rotate said precisely actuatingmember.
 15. The image tilting device according to claim 14, wherein saidelectromagnetic driving element comprises: a yoke, which has apredetermined shape for easily generating an electromagnetic force andbeing attachable to said precisely actuating member; a permanent magnetfor forming a magnetic field by attachment to said yoke; and an electricwire, which is disposed between said yoke and said permanent magnet soas to form a magnetic field with said permanent field.
 16. The imagetilting device according to claim 15, wherein said predetermined shapedyoke has a plurality of branches disposed in parallel.
 17. The imagetilting device according to claim 15, wherein said electric wire is acoil wound around the branches of said yoke.
 18. The image tiltingdevice according to claim 15, wherein said precisely actuating meanscomprises at least one connection, which contacts with saidelectromagnetic driving element, in order to transmit a mechanicalenergy of said electromagnetic driving element to said preciselyactuating member.
 19. The image tilting device according to claim 15,wherein said electromagnetic driving element is disposed at both ends ofsaid precisely actuating means.
 20. The image tilting device accordingto claim 4, wherein said support portion, said hinge portion, and saidrotating portion are made of a material having an elastic restoringforce.
 21. The image tilting device according to claim 20, wherein saidmaterial is aluminum.
 22. The image tilting device according to claim20, wherein said material is plastic.
 23. The image tilting deviceaccording to claim 3, wherein said light path conversion means is areflective mirror.
 24. The image tilting device according to claim 3,wherein said light path conversion means is a refractive plate.
 25. Theimage tilting device according to any one of claim 23, wherein saidimage tilting device further comprises: a frame of a predeterminedheight which comprises a protrusion portion at one side for supportingsaid light path conversion member; and a supporting member, which iscovered at the other side of said protrusion portion of said frame toprevent said light path conversion member from bending.
 26. The imagetilting device according to claim 25, wherein said frame of said lightpath conversion member and said precisely actuating member respectivelycomprise a projection and a groove for assembly.
 27. The image tiltingdevice according to claim 26, wherein the image tilting device furthercomprises: a frame of said light path conversion means and a fasteningspring for fixedly mounting the support member above the preciselyactuating means.
 28. A projection system comprising: a light source,which generates a white light; a color-processing means for imparting apredetermined color to the white light from said light source; a microdisplay means, which can display a predetermined image by using thelight processed by said color-processing means; at least one projectionlens which projects an image displayed on said micro display means; animage tilt means which precisely rotates the image inputted from saidprojection lens to then convert the path of the image to be transmitted;and a screen, which magnifies and displays the image being rotated bysaid image tilt means.
 29. The projection system according to claim 28,wherein said projection system further comprises an optical means forimaging the light processed by said color-processing means.
 30. Theprojection system according to claim 29, wherein said micro displaymeans is disposed so that a pixel is reflected obliquely on said screen.31. The projection system according to claim 29, wherein said image tiltmeans precisely rotates so that the image reflected on said screenthrough said light path conversion means moves toward the direction ofthe diagonal axis of said screen in a reciprocating manner.
 32. Theprojection system according to claim 31, wherein said image tilt meansprecisely rotates on the diagonal axis of said light path conversionmeans.
 33. The projection system according to claim 28, wherein saidimage tilt means comprises: a casing; a precisely actuating means whichis housed within said casing and is integrated so as to preciselyreciprocate; a driving means which contacts to said precisely actuatingmeans to drive said precisely actuating means; and a light pathconversion means, which is disposed on said precisely actuating means toconvert a light path by the precise movement thereof.
 34. The projectionsystem according to claim 33, wherein said projection system furthercomprises a control wave generation means which generates a control waveto control the movement of said precisely actuating means.
 35. Theprojection system according to claim 34, wherein said control wavegeneration means generates a resultant wave of such a shape that theflat portion of a square wave is linked to the rising portion or thefalling portion of a sine wave.
 36. The projection system according toclaim 35, wherein the flat portion of said combination wave is composedof an upper flat portion and a lower flat portion, each flat portionhaving at least one step.
 37. The projection system according to claim36, wherein said at least one step is symmetrical to one another at theupper flat portion and the lower flat portion.
 38. The projection systemaccording to claim 33, wherein said precisely actuating member comprisesa predetermined plate-shaped support portion; a first hinge portion ofbottleneck structure extending vertically upward, which runs from oneend to the other end of said support portion; and a rotating portionwhich is linked by said hinge portion to be disposed on said supportportion, and precisely reciprocates and rotates left and right on theaxis of said first hinge portion.
 39. The projection system according toclaim 38, wherein said support portion is plural.
 40. The projectionsystem according to claim 39, wherein said plurality of support portionsare linked up and down by a second hinge portions of bottleneckstructure extending vertically upward which runs from one end to theother end of said support portion.
 41. The projection system accordingto claim 40, wherein said second hinge portion is perpendicular to saidfirst hinge portion.
 42. The image tilting device according to claim 6,wherein said support portion, said hinge portion, and said rotatingportion are made of a material having an elastic restoring force. 43.The image tilting device according to any one of claim 24, wherein saidimage tilting device further comprises: a frame of a predeterminedheight which comprises a protrusion portion at one side for supportingsaid light path conversion member; and a supporting member, which iscovered at the other side of said protrusion portion of said frame toprevent said light path conversion member from bending.